Apparatus for evaporating moisture-containing materials.



G. D.-HARHIS.

APPARATUS FOR EVAPOHAUNG MOISTURE CONTAINING MATERIALS. APPLlcmon min nov. n. m5. nfucwzo :uw as. ma.

mmm/r nHczrrL's Patented Mar. 4, 1919.

v To all whom it may concern.'

Island, and State of New perceptible extent, it may GORDON DON HARRIS, 0F FREEPORT, NEW YORK.

APPARATUS FOR EVAPORATING MGISTURE-CONTAINING MATERIALS.

Speelcation of Letters Patent.

Patented Mar. 4,1919,

Continuation of application Serial No. 739,603, led January 2, 1913. This application led November Il,

1915, Serial No. 6,889. Renewed July Be it known that GonooN DoN HARRIS, a citizen of the United States, residing at Freeport, in the county of Nassau, Long York, have invented a certain new and useful Apparais for Evaporating ll/Ioisture-Containing Bf terials, of which the following is a speccation.

This invention is an evaporator for eliminating moisture from various materials, wherein. Va drying medium, such as air warmed to a suitable temperature, is utilized for eliminating moisture from the material under treatment, whereby eiciency and economy are obtained. Although it is preferred to employ air as the medium for carrying heat to the material under treatment, it is apparent `that the direct heat from a furnace, or furnace aerases, or boilerroom gases, may be utilized as the emporating agent, particularly in the treatment of materials containing a` high percentage of moisture, such as peat, which n'iaherial is not injuriouslyv aliectcd by high temperatures. Again, superheated steam may be employed as the evaporating agent, the same being particularly useful in the treatment of certain materials which require the utilization of both heat and moisture in the dryingof the material. as in the case of the oxidation of the coatings applied to linoleums and similar sheet or web materials.

The apparatus of this invention is useful in drying many different kinds of materials, such as peat, various kinds of fertilizers such as humus and phosphates, paints or paint materials, such as white lead, linoleums and similar web or sheet-like moisture carryin materials, soap, and in fact any and a inoisture containing substances.

As a 'drying medium, I may use air heated to a predetermined temperature, such drying medium when brought into contact with a moist material absorbing .a` certain perce-ntage of moisture from such material, as a result of which the temperature of the drying medium is lowered to an appreciable or be one degree or more, according to the temperature of the material under ltreatment and to the amount of moisture absorbed therefrom. To attain vmedium is heated 'perature, say 240 Fahrenhei 16, 1918. serial No. 245,236.

economy of operation, the present invention utilizes the drying medium repeatedly by bringing it into contact successively with layers of material, in contradistinction to some prior systems vherein air is circulated once only into contact with the, material, i. by introducing warm air, conducting it over or through the material so as to absorb moisture therefrom, and immediately dischargin 'the air.

The circulation of a warm or heated drying medium into contact successively with different layers of material to be dried reduces the temperature of such medium, for the reason that the evaporation of moisture cools it, and should this operation be oarried on indefinitely, it follows that the medium will evaporate moisture to the point of saturation, thus resulting in a substantial decrease in the temperature of the drying medium, at which and moisture saturated drying medium will practically lose its efficiency. `v

overcome the foregoing objections, Aand attain the purposes of my invention, by heating a drying medium in the intervals be tween its contacts with the material under treatment, whereby said gaseous medium is maintained at a imiformtemperature, notwithstanding its repeated contacts with the material, thedrying medium being expanded g in volume by the successive heatingr Orem-4 tions for the purpose of increasing its moisture evapouating capacity, whereby the drying medium is conditioned to render it suitable for repeated contacts with the material or until said medium shall have 'become saturated with moisture up to a, certain4 point.

According to a preferred embodiment of time the' relatively coolf v' this inven'tlon, a large volume of the drying ,to e prede wending upon the nature of the material under treatment; this heating gaseous medium is com ducted into conta/ot (either directly or indirectly) with a layer of material, as a result of which it evaporates moisture and its temperature is lowered, say 1 or to 239c Fahrenheit/pibe gaseous a ium than Hows into contact with a boostensuch es e steam 4coil or other ined tems.'

beaten-by which said" medium is reheated to thc original temperature, 240 Fahrenheit, und thus expanded to render it capable of absorbing,r more .moisture; the drying medium flows again into contain*J with a layer of material, thus n bsorb ing'more moisture and slightly cooling it, Say again to 239'o lflahrenheit; the aseous medium is again boosted or relient-e( to re- Store it. to the initial temperature and to expand it. for the absorption of more moisture, and so on throng lout the treatment,

juntil said gaseous medium acquires a oer- -absorbing moisture up to a. certain tain saturation of moisture. It is thusappurent that the drying medium 1s brought into Contact with the successive layers of material, and that it is repeatedly heated and expanded, for rendering it capableof point, whereby economy of steam is secured 1n .the Voperations of heating and reheatm the dryng medium, as a result wher-eo rapidity "the heat inlet are insufficiently dried, lLhus establishing ineliiciency of operation and irc volving aV wastuge of energy, for the reason that the `dryingr o erationjmust be continued for such a lengt of time as to evaporare the material on cheV trays remote to the heur inici, as e result of which the layers of inuterial adjacent to the heat inlet became dried to an excessive degree and such motorini thereby is broughtto what may be termed a burned condition. Again, in the drying or evaporating of any kinds df material the layers owing to excessive heating in the drying medium acquire a superficial coating or skin which to a material extent precludes the free transudation of moisture from the interior to the surface of the mass or the constituent parte thereof.

My invention overcomes the foregoing rious objections, 'for the reason that euch layer of material is subjected to identical treatment by the drying medium the temperature of which is such as to effect the desired eichanp,r of heat for moisture While at the same time the treatment [cuves each mass of material in u condition for thc free transudution of moisture from thc interior of such niassfonhe constituent parts thereof. The dryingiinedimn is heated to :i temperature suilcdto the n'roisture contentV of the man rial, and as such moisture content: varies in l different materials il. is appa-rent` that the drying mediums for the treatment of such different materials will be heated to diiicront temperatures; but in every case, the temperature of the drying medium will be so proportioned to the moisture contientV of the particular material to be treated, and the duration of the treatment will be such, that while the desired exchange of heat from the drying medium for moisture from the material will be eflected, still the drying or evaporating operation will leave the material in the desired condition for the free transudation of moisture, each .and every one of the layers of material throughout the series being subjected to identical treatment for the reason that the temperature of such drying medium is uniform throughout its flow into Contact with the successive masses of material as a yresult of which the nuisses of material ure thoroughly and uniformly dried in a rapid manner and by steun: economically used under favorable conditions, each muss of material being free from a superficial coating upon the exterior of the mass or upon the constituent ports thereof so that the moisture content is free to transude from the mass under the conditions of treatment secured by this invention.

Other features of the invention, und the advantages thereof, will appear from the following detailed description, token in counection with the accompanying' drawings, wherein- Figure l is an elevation of a drier embodying* this invention.

Fig. 2 is a vertical section laken in the direction of thc length of the apparatus, illus tration; one of the material treating chambers und n series of trays therein, together with the boosters or heaters associated with said material-trentino' chamber for boosting the temperature of ,the moisture curryfinp,r medium in the intervals between its contacts with the material on said trays.

Fig. 3 is n vertical section in the plane of dolted line 33 of Fig. i2.

A designates a casing: the interior of which is divided longitudinally und ironsvcisely, as will hereinafter appear, for the purpose of producing n series of .materialtrenting chambers. Combined with said onsing a flue into which u drying medium, such as atmospheric air` is admitted for the purpose of preheating the nir prior to its admission to sziid material-treating chambers, und a separate fllul into which warm air from the inuteriuhtrenting chambers is discharged in such u manner thatl the heat i of .the outflowing warm air is utilized to ndvnniagc for preheating the inliowiug air.

Casing A is divided transversely by vertical partitions B into the series oi' materialtreating chambers, access to which chambers is obtainable, by doors b provided in the frontyof said casing. A

Each material treating chamber is divided by substantially horizontal partitions B B2 into a scrive of compartments and a series of heating or boosting chambers, but, as the construction ofleach matcrial-treat ing chamber is the same throughout the apparatus. a description of one of said chambers will answer equally for the others. At the top ot' each material-treating' chamber, partition ll and the top wall of the casing forms a chamber C, into which the drying' medium flows through a suitable inlet c, said chamber C contaming means for warming the air to a temperature suitable for the treatment of the material which is contained on trays D, supported within the compartments of the chamber. `The means for heatinar the air to the required temperature just prior to flowing into contact with the mat-erial is shown as a heater comprising live steam coils E, said coils being of such capacity and number that the air, preheated or otherwise when admitted by inlet c into chamber C, will as said air flows into contact with coils E, be raised to a temperature suitable for treatingr said material.

Partitions B B2 are positioned alternately with respect to each other and within the material-treating chamber, for the purpose of producing a series ofcompartments F,

said partitions extending from one wall of the chamber nearly to the other wall thereof. lVithin these compartments are provided angle irons al for supporting foraminous trays D, or their'equiv'alents, whereby the material is supported in layers within said compartments F for the drying medium to circulate over and beneath `the material on said trays. In each compartment the an le irons are positioned to sustain trays D 1ntermediate the substantially horizontal partitions B B2, in order that the drying medium may flow above and below the material on the trays.

Each tray D is :positioned between two partitions, so as to orm therewith two passages, one above the tray and the' other below said tray, so that the drying medium will flow in a circuitous or zig-zag path through each compartment. Furthermore the tray and the two partitions adjacent thereto are relatively arranged t'o secure taperin' pas` sages, the intake ends of which are argelthan the outlet ends; as shown in Fig. 2, the

tray is horizontal. the upper partition is inclined. in'onevdirection with respect tc the tray, so as to produce a passage which tapers in one direction, whereas the lower partition is inclined in an opposite direction with respect to the tray so that the lower air as- 'sagre tapers in the opposite direction. he passages above and below the tray open into 1the heating rMembers, so that the drying medium flows from above the tray into ourl heating chamber, thence below the tray into 4formly with, the gaseous the next heating chamber, and so o'n through the compartments successively the heating chambeis in like order.

The purpose of inclining` the partitions relatively to the trays so as to produce the tapering passages is to retard the flow of the drying medium through said passages and while in contact with the masses of material upon the trays. By thus checking or throttling the flow of the dryin y medium while in contact with the materia said medium is controlled or put under compression while circulatin through the compartments, and as a, resull: the drying medium is directed against, and into intimate contact with, the masses of material, on both the top and bot tom surfaces thereof, such intimate contact of the dryingr medium with said surfaces of the material securing increased eflicienc in the operation of evaporating moisture om each layer or mass of material.

According to my invention, the direction of flow of the mediatelyY fol owing its interval of contact with the material and prior to the next contact with such material, and at o1' during this period of reversal in the direction of flow,

aseous current 1s reversed im,-r

and through 4 the drying medium is conditioned so as to i ,render it capable of evaporating more moisor reheater positioned within said chamber. Thedrying medium flowing out of one passage, and bearing a certain proportion of moisture, is brought immediately into contact with the surfaces of the booster or reheater, as a result of which the said medium is expanded and agitated so as to diffuse Vthe moisture throng and mix it unidrying medium, which diffusion of moistur when taken in connection with the step of reheating the dryin medium so as to restore the temperature lost by the previous evaporation of moisture), brings the drying medium into a superior moisture absorbing condition prior to said medium flowing again into contact with the material. These operations of restoring the dryiiacr medium to a proper condition for absorbing moisture take place between the contacts of said medium with the upper surface and the under surface, respectively, of each mass of material, and, also, between the contacts of said medium with the successive masses.

As shown in the drawings, the drying medium is admitted at the top of the treating chamber and flows back and forth therein,

or in a circuitous path, in a generally downward direction and toward the exit Pos1- tioned at the bottom of said chamber; but it is apparent that the general direction of tl'ow may, if desired, be reversed by conductln the drying medium generally in an upwar direction.

It will be noted by reference to Fig. 2 that the horizontal partitions B B2 extend from one wall nearly to the other, and that in the space between the short end ofthe artitions and said' other wall is a series of ort horizontal partitions B, the latter being substantially in the horizontal plane of trays D. The trays do not extend the full length of the horizontal compartments F. The artitions B' B2L Bi and the trays are so re ated, that heating or boosting chambers G G are provided at the respective ends of the traycontaining compartment. A suitable number of these tra -containing compartments are provided wit boosters or heaters H H', the same being adapted to utilize live steam asf'the medium for heatin the air, but below these steam boosters or` eaters H H', it is preferred to employ `other boosters or heaters I I through which hot watery is adapted to circulate. The convolutions of the hot water c oils I I increase in number in the successive coils, that is to say, after the drying medium ows out of the compartments containing the live steam coils, it is bron ht into contact with one hot Water coil I havin four convolutions, the next hot water coil contains five convolutions, and as the nir flows into contact with the succeeding coils the convolutions of said coils increase in number. Y

A salient feature of this invention is the Vemployment of means for boosting or reheating the drying medium each time it flows into Contact with the material on the trays, and in the embodiment shown, the boosting or reheating means consists of steam coils H H and hot water coils I I', two of said coils being positioned at jthe respective ends of euch tray, so that as the drying medium flows over one tray it is brought into contact with one coil, it then Hows be neuth the tray and is brought into contact withl another coil by which it is boosted or reheated before it flows over the next tray, and so on throughout the series of compartrgients F within the material-treating cham*- In my apparatus the drying medium admitted to chamber C and brought into con` tact with the heating coil E, is conducted in a circnitous path and into repeated contacts with ,the material resting upon the trays D of all, the com artments within the materialtreating cham r, said drying medium. Howing back and forth, over andY beneath the trays, and from one compartment into the otherpwhereby the entire volume of the drying medium su )plied eontinminsly to each chamber is conducted successively into ecntact with the separated layers oi material. The drying medium when first admitted is raised to a temperature suitable treating the particular material loaflc npon the trays, and as it flows over the mite/rial upon the first tray its temperature es slightly decreased, owing to the fnct that the drying medium gives ot? some of its nent and abserbe moisture from the material; but said drying medium is immediately AVronght into contact with the booster or ter H', by which it is restored to the initial tempera ture as it flows beneath the iirst tray. After passing below the lirst tray, the drying medium flows into chamber (if and into contact with the booster coil H therein, by which it is again restored to its initial temperature before it flows over the second tray, wbereupon the drying medinfo. Howe lirough chamber G and into contact with the booster or coil li" so that it is retreated be fore it iiows below the second tray. These operations of conducting the drying medium over and beneath the trays. and into corr tact with the boosters or heating! ils before it passes into the succeeding compartments, are repeated throughout thel several comartments of each material-treating chamer, and finally the drying medium flows ont by un outlet J.

The employment of the boosters or heating coils H ll l", et. the respective enfle ot the trays, or in 'the chambers at the ends of the tray-containing connnirtnicnts, provides efficient means ier keeping the drying medium at a normal or l'lredetcrinined temperatnre in order i1;- obtnin eliieiency in the evaporation of moisture from the nateriai, but a marked feature of the invention is the very great economy of fuel required for heating or imosting the drying medium. As hcreinbefore stated, the drying medium preheated prior tc its admission tothe ma ternl'treztting chambers. it is broi'lght up to the temperature required in; contact with heater E; any slight decrease in the tcmperature due. to the Contact of said medium with the material vill result in tire medium being brought baci; to a standard tempert ture by contact with one or more of the boosters or coils H H l I', and thus, while Vtlie medium is used repeatedly byrcntact wiith the successive layers of material, the temperature of said lnednnn 1s maintained at a predetermined standard by the boosters `or coils, as a result of which no very great expenditure of fuel is necessary tu maintain the drying medium at the pr Amined temperature, and very great ottime: y and economy is thns obtained, for the reason that the drying medium when heated at this temperature will he expanded in .'elnrne and have a capacity for absorbing moisture from the material under treatment Without, however bringing the heated drying medium to a condition wherein it will be saturated with moisture or placing it in such a condition as will result in the deposition of moisture upon the material.

Vhe apparatus herein shown is constructed with a preheater of a particular form. Extending longitudinally of the casing, at the rear of the material-t`reating chambers therein, are vertical parallel partitions K L which produce an outlet flue or chamber is and an inlet flue or chamber Z. TheV exits from the material-treating chambers open into exit chambers Z5, whence the moistureladen air flows through an exit le adapted to discharge into a stack or uptake, orY at any other suitable place. The air is blown into chamber Z by a fan L having a connection Z' with said chamber Z, and with this chamber Z communicates the openings c of heating chambers C, whereby the air preheated in chamber Z is free to How through openings c into the series of chambers C at the upper ends of the material-treating chamers.

The chamber l: is positioned between the material-treating chambers and the air preheating chamber Z, and in the apparatus shown the heat present in the air owing out of the material-treating chambers is utilized for preliminarily heating the iniiowing air which circulates vthrough chamber Z. To this end, baiies` m m areY positioned i 'ithin chambers lc Z, respectively, and v hcat-transmitting battles a ,fo are provided on the partition L` and within the respective chambers Zr Z. Preferably, the partition L and baffles o ,c are composed of a metal rsen- The Warm air from the material-treating chambers flows into exit chamber c, and into contact with copper partition L and copper baiiles 0 the warm air being directed toward partsL 0 by one or more baiiles mi. The air is thus brought into contact with the arts L o for the purpose of giving ofi' its heat to these parts, whereby the heat will be carried by partitions L into chamber Z. The air flowing' into the chamber through inlet Z is brought into contact with the partition L and ba-les p, the inlowing air being directed toward the battles p by one or more balies m'. As a result, the infiowing air is preliminarily heated before its admission to chamber (l, and the heat contained in the outfiovving air is utilized for preheating the inliowing air.

The t'oregoing'Y description sets forth with articularity one type of preheater, the same icing positioncd rearwardly of the material-treating chambers. Obviously, other forms of preheaters may be employed for the drying medium, and, further, said pre- M5 heater may be positioned at any suitable lowered, but before Sitive to ythe action of heat, such as copper.

point relatively to the treating chamber or chambers;

The operation will be` foregoing description, but may be summarized as follows: Y

The material is loaded upon the foraminous trays D, and the doors Ig to the material-treatin chambers being o en the filled trays are placed upon the ang e irons d, for supporting the trays and the material With in the compartments F'. The blower circulates air through the preheater and the chambers C, the outfiowing ain through exits J into the preheater an thence through exit Zr. As the air flows into the preheater, it is heated bythe Warm air fiowmfr out of the preheater, and 4as the air flows through chambers C and into Contact with coils E, such inflowing air is heated. Yto the temperature acquired, say to 240 Fall` renheit. The air flows back and forth through each compartment F,and successively from one compartment into the other. The contact of the air with the material lupon the trays results in the absorptionof a certain amount of moisture from such material, so that the temperature is slightly the air is brought into it .Hows into Contact again with the material the boosters contact with one or the other of or heaters, slightly raise so heat lost by th whereby the temperature of the air is maintained at a predetermined standard, notwithstanding the loss of yheat and absorption of moisture due to contact with the material.

he air is used i r the intervals between its contacts with the material, thus resulting in economy and etricienc y of operation, in the outowing air, after such air leaves the material-treating chambers, is utilized in the preheater for the purpose of preheatmg the mflowing airf l It is evident that various changes in the as to restore to the air the .structure may be employed. In the drawings I hate shown each material-treating chamber as being se pendentfoif,` the ot chambers', bt it may er material treating passing.

b which the temperature is repeatedly and is heated in but the heat present apparent from the soV e absorption of moisture,

arate from, and indebe desired to circulate the air from one chamber into the otherchamber, as forI example-when it is desired to evaporate moisture ro a material which is slow to give oil' its moisture. Furthermore, the means for supporting .the vmaterial Within the compartments ofeach treating chamber may be modified, in which case the trays may be dispensed with, and suitable endless belts or aprons employed for imparting movement to the material while treating it. Furthermoravdampers or valves may be placed at various points for ,controlling the circulation of air, but as all the'sefeatures are well known to hose'skilled Am the nrt, have not considered it necessary to illustrate the seme in detail.

It should be stated that the temperature of the drying medium when admitted to the cheplbers will be such as is best calculated to evl 'crate moisture from the particular me te l under treatement. Thus, in treating V,nneriel which will readily give off moisdrying medium the temperature of which verles within wide limits, but in all instances the means for boosting or reheating the dryin medium operates to maintain it substantie ly et a predetermined temperaturegjor'the reason that the loss in temperethe materiel-,supporting hailed air.

tureidue to the contacts of said medium with the material will be offset by the action of the boosting or reheatin coils, the drying medium being conducted into direct contact therewith es it circulates successively through the chambers. Furthermore, it will be noted that the partitions and devices are inclined relatively to4 euch other, in order that the drying medium will How through tapering space'sznbove and below the trays, w icreby the dryin medium flowing above the tray is directe against, end into intimate contact with, the material on such tray; willv l ise be conducted into intinm'tc contact"K with the materiel thereon. The drying medium thus circulates in a manner to have a direct und intimate Contact with the material which is supported in separated layers within the several compartments, the llurgeyolume of nir supplied by the biower being reheated, used continuously und repointedv y in direct contact with the material, and `reheeted at fre nent intervals so as to maintain the air su tuntinlly at the predetermined temperature, and in an efiicient moisture-absorlnn g condition.

The moisture-leden air from the materieltreating chambers (one or more)` flows under tessure into `an exit chamber k of reason of such Eressure the gir is circulated through'said c amber k und discharged through exit puringsnch Youtflow .ofthe wenn am', 1t is chilled, in a' measure, b parting with its heat in order to Preheat t e air flowing onto the preheiiter, but should it become necessary an exhauster may be used et .theautlet in" for discharging the moisture-laden The resent application is a. continuation of an includes Vmatter resented in my prior-ep licetion Serial o. 789,603. The process erein disclosed of treating moieturc-containing materials forms the subject und as Y sind d` ng medium liows below the tray, 1t

mutter of n divisional application Serial No. 60,590.

Hoving thus fully described the invention what l claim as new und desire to so curo by Letters Patent is:

l. in un evaporator, the combination of a scrivi1 of compartments, moans positioned therein for supporting nmtcriul in Separuted nmsses, one muss in euch compnrtment, Ineens for heating a drying medium to n predetermined temperature, means for circulating; such drying medium `buch and 'Forth above und below the motorini within euch compurtmcnt and successively hrougii the serios ol' compertinents` :mel means AKor rebooting,y the drying medium 'to the preW determined temperature as it iiows from one compartment into the next und also for reheating the drying medium in the interval between the contacts or such drying medium with the upper und under surfuces ol' the mass of material in each compartment.

2. In `an, evaporator, o. treating chamber, means for supporting materiel in separated :liasses therein, means for heating n drying medium to a predetermined temperature, means for circulating said drying medium buck and forth above and below the me teriul, means opposing the {low of the drying medium in presence of each mess of material sind while in contact with the upper and under surfez-,es of such mess, and reheaters iositioned for the drying medium to flow into contact therewith so as to relient the drying medium in the intervelsA between its contacts with the successive messes and. with the upper sod under surfaces of euch class,

3. ln er. evaporator, the combination ot a series, ot' compartments, means for sl' porting material to be treated in seperated masses respectively in each compartment, means for prehenting a drying medium to a desired temperature, ineens for circulating such a drying medium within the compartments und successively through them, end rcheaters in the path of the drying medium for reheeting sind medium so es to maintain it at the predetermined tempera ture, in the intervals between its contacts with the successive messes, the walls of seid compartments bein positioned 'with rei'erence to the mnteriaisupporting means so ne to o pose or retard the flow of the drying medium Wh'rlcin the presence of the masses of material and 'to thereby secure en intimate contact of the drying medium with such material.

4. In an evaporator. n. treating chamber, partitions separating tue chamber into compartments other partitions dividing the chamber into heating Vesi-teigne, materialholding trays located in' each compartment and extending longitudinally of the same and dividing ouch compurtment into two passages. News for circulating; e drying material under medium and forcing it through the heatin assagesand through the passages formed )y the trays, means for heating the incoming drying medium at such predetermined temperature, as it flows into Contact with the treatment. 5. In an evaporator, a treating chamber, partitions divi( ing said chamber into a series of heating passages, other partitions dividing the chamber into a series of material-holdingcompartments, material-holding means supported `in each compartment and dividing the same into two passageways so arranged in relation to each other that the exit end of each passageway is smaller than the entrance end thereof, the said passage- Ways communicating with the heatlng passages, means for supplying a drying medium to the treating chamber, means for heating the dryingr medium, as it is supplied to the chamber, to a predetermined temperature, and means Within the heating passages to maintain the drying medium at a predetermined'temperature during its contacts with the successive masses of material.

ti. In an eva orator, a treating chamber, partitions for L ividing said chamber into a series of nulterial-treating compartments and into a series' of heatin passageways, material-supporting means or hoidingthe material in separated masses, one mass in each material-treating compartment, said partitions and the materialsupporting means being arranged with respect to each other to produce tapering passages the exit ends of which are smaller than their intake ing chamber. the flow ero ends, means for circulating a dryingmedium through said heating passageways and through the tapering passages so thatV within the latter the How of the drying medium is retarded and directed against and into contact with the masses of`material and means' for reheating the drying medium during its circulation, said rehcating means being positioned within the heating passageways.

7. vIn an evaporator, a treating chamber, partitions for dividing the chamber into a series of compartments, means within said compartments, said partitions and the material-holdingmeansbeing relatively arranged t'o produce tapering passages extending respectively above and below the material-holding means, means for circulating a drying medium through the treatof such drying metapering assages being retarded so as to result in tlie drying me- -dium being directed against and into coni tact with the material, means for heating the drying medium to prior to its circulation, and means for reheating the drying medium during its circulation so as to maintain it substantially at a predetermined temperature.

dium through the material. and means `tor rcheatin material-holding a desired temperature 8. In an evaporator, a treating chamber, partitions arranged to divide said chamber into a series of material compartments and two series of heating passageways, materialsupporting means Within said material compartments, means for initially heating a, drying medium, means for circulatingthe drying medium through said material compartments and the heating passageways, the relation of the material supporting means to the walls of the compartments being such as to throttle the flow of the dryinir medium Within said compartments and 1n the presence of the material therein, the direction of flow of the drying medium being reversed by and within said passageways, and means Within the passageways for reheating the drying medium during such reversal in the direction of How, whereby the drying medium is maintainedat a predetermined temperature. Y

9. In an evaporator, a treating chamber, means for supporting material in separated masses therein, means for heating a drying medium to a predetermined temperature,' means :For circulating the drying medium into contact with the lseparated masses of material, means for throttling the flow of the drying medium in the prcsenoelof each mass of material, means for reversing the direction of flow of the dryingjlmedium subsequent to its contact with each mass of `the drying medium at the time ot' reversing its dinl i'ection of flow so as to maintain tli'e drying medium at the,predetermined temperature.

1,0. In an evaporator,` the combination with a series of compartments, an'd means for supporting material for circulating a drying medium back and forth within each compartment and successively throu yh the compartments of the series, whery the drying `inedinm is brought into contact repeatedly with said material, and reheaters in coperative relation to said compartments for the drying medium to flow into contact therewith.

11. In an evaporator, the combination with a series of compartments and meansfor supporting material therein, of means for circulatinga drying medium back and forth within each compartmentand successively from one compartment to the next, the walls of Said compartments op said drying medium whi e in contact with the upper and under surfaces of the material in each compartment, means for initially Vheating the` drying medium to a predetermined temperature, and means for reheatin the drying medium while circulating it through the compartments.

12. In an evaporator, a'series of compartments, means for supportin in, means for circulating a drying medium back and forth through each compartment therein, of means* osing the flow off and successively through the compartments so that the drying medium will iow into contact with the upper and under surfaces of thev material, and rebooter-s positioned in the path of the drying medium circulating through the compartments.

steam coils in cooperative relation to certain of said compartments, and hot water coils in cooperative reiation to other of said compertinents, the live steam coils being nearer than the hot water coils to the inlet point ot the drying medium and all of said coils being in the pat-h of iiow ot' the drying inedium.

14. In an evaporator, the combination of a series of com crimen te, means for supporting material t erein, swans for circulating a drying medium bach Find forth through enel! compartment and above and below euch material-supporting mesas, and reheaters positioned in the path of the drying medium.

15. In an apparatus of the clase described, the combination with a chamber, means for supporting therein material in separated masses, and means for circulating a drying medium within said chamber, of means for reversing the direction of iow of said drying medium whereby it is caused to i'low into repeated contact with said masses oi materiai, and means for reheating said drying medium,l said rebeating means being positioned adjacent o the points at which occur the reversal in t e direction ot flow of said drying medium. 16. In a `apparatus of the class described, the combin tion with a main chamber, and means for supporting therein material in separated masses, of means 'separate from the material-supporting means and positioned for dividing said main chamber into a, series of material chambers and into a.

series of heater chambers, said heater chin-sine with the separati-d masses at n temperature bers beinA positioned at the ends of :sind material c embers and each heater chamber beingin communication with two` of said material chambers, means for circulating a drying medium wi hin the material chambers and the heater chambers, and means positioned Within the heater chambers and in the path of the drying medium circulat 1ing therethrough for retreating said drying medium in the .intervals bctweenrits contoets with the successive masses of material, whereby the drying medium throughout its How into successive contacts with the separated masses is kept at a temperature which leaves each mass in a condition for the free transudation of moisture while the contact of said medium with the moss is effective in exchanging heat for molsture.

17. In an. apparatus of the class described,

the combination with a main chamber, and

isolate said masses of material and io direct the dryingr medium into contactl with said masses, and rrheaters positioned within the heater chambers for reheatingihe drying medium in the interval between its con tants with said masses of material, whereby the drying medium throughout' its How into successive contacts with the separated masses is kept at a temperature which leaves cach mass in a condition for the free transudation l of moisture while the contact of said medium with the mass is effective in exchanging heat for moisture.

18. In an apparatus of the class described, the combinntion with a main chamber, and means foi-supporting therein material in separated masses, of dividing means separate from said material-supporting means, said dividing: means being Within the main chamber and positioned to subdivide the same into a serios of material chambers and a series of heater chambers, means for circulating air Within said material chambers and said heater chambers. said dividingr means serving to isolate said masses of material and operating to direct the fiow of the drying medium in a back and forth direction through the main chamber and successively throughout thc umterial chuuibcis and the heater chambers, means for preheating said dr/ying medium to a doeii-cd telnperature, and means positioned within the heater ch bers and in the path of the drying medi un for maintaining the latter throughout its How into successive Contact mzisps of material und operating in direct said drying' u'uilium in :i heu-ii une! furti] direction within thv 11min 'huiiiui anni auw cessively ilu-(umh the umtmizil-conmining compartiments tiuwim und i'ahmuffi's mi# tiouefl in Upfaruiiw i'viuiimi tu thv material- ('mitriiuiuiil wulpui-lnwnts :mal iu flip umh ui" the drying medium au uw iu mum-,f than wih ut Ihr puiniu .fir whivh mf'ur iluVl vhaugvs iu tlm :lircriiou 0l' How (if file. drying medium heli-ahy Suhl rllyiugr iumlium is maintuiimi in :i rfmulitimi if lesiva: all ihn masser@ ni' uuii'vi'iul iu u trunsuflutmy condi; tion while` securing the dpsired exchunge uf heat; for moisture. i

20. In an nppumtug uf the class (iesciil'ienl, thc i-mnhinutmu with u main chamber, and moans for supporting thviein material in .Separated massa ni' dividing mmins wimluir from the u1sitvr'iahuipporiing mums, suini dividing :iusuis living fmsilionml within .filo main vhfiiilwi' um! suhdividing h@ intim' intu n` serias (if ifouipiuirwins zuluptml for L'mliziining thi umii'iui-Huppm'iing mineur;` moans for i-irf'uiui ing :i li'ving n'uilium. Suid divi-ling ummm serving if isoiufe @mili masses m" umlmial :imi oper-:ximg te fiir'vcr the Huw if the drying uwdiuni thrnugh the rompu??- nwnth sufrwsxiviij; :mil ihm wmizui viii! Huf humm i'iiufvisi. und humus pmiiimu-i in thv iiiteifi'nf" iu'wemi fauiil umtvi'ialimminiiig: fliulri? ffii' Conditioning Suid drying iiuuiiuz-= -r. than .'hu, minfin-tir ai' said medium with thc :MPOMSijJu maw-'M z-xffhnuges iaizii,

im' tunisini@ und humax auch mush m aiV 2i in im zippzuzii'izs (ifjiw vliis; iiosil'ibm, iiw mmhimii'inn Wiih u` iuzliu vimmhvy, :smi humm iui' supporting ilwwiu nintaifiui in Hupzirzi'eii nizw-ws, if dividing mouw; sfpam rule fium mili nuxie'iiuLriuppniiIig means said dividing' mmm living ,funsiiimieci withiu ilu 11min cluu'nlwx' um] subwiiviiiing he hitter iuu u swirls* o vuxifpau'ruwufs adapt vri fur muuuiiug hv naiiiii-l'ialsuipm'iug :1u-uns, :mmm fnl' viii-dining wir. moans ffii* l'u'eiumting uil' lf: u issiifi {insign-rali uw, said dividing ilu-:ms sowing w imhatvmi imuewu uf material :mil if iirvrj lli@ How 0i' ih@ pi'vhvuimi uilY through this Qiumfiisivf com parimenti; zum] iut() Contact, with the nuit?h rial thx-rein. uml mzfuns pusitioriad mijiuut flu!V matoriuhsupimriing' inuurfm' ruhoatirig (he uil' in the inturvuh; hath en its contacts with the masses and tu ihiemhy cunclition ille nii' throughout its How sa ais t0 render this same el'eetive when in @unmet with the mussns for exchanging heini: im' moisture und to heave auch muss: in n ti'nnsluihtol'y cmidition.

22. In an apparatus of the class denctihed, the comhinamn with a mam chamber, and means for supporting mutex-uli m separated masses therein, of dividing menus positioned for mib-dividing said main chamber into a. hariw; mi muiipurmmis adapted for cont-ain ing reflui zimei'iii-supporiug means, moans im' viri'uhiring air. means for prel'ienting ail', misi dividing iiwasus bei-ving to isolate said mma@ n? nmi'risi :imi t0 direct the HOW of hv pl'viuuluei nii' ucr-issiwly 'through Suid uumgmtmmits :imi into intact with the :misses :im-ain, mui rehuatrs positioned in ihn with m Huw nle the nii' and intonrudiate [iw mata iii-supporting mmlns for @muliifiniiigj iup fuif throughout: its #inw into su@ iasuive i-esniiwfs with the masses of mntegiial. iii an iippsirutus of the class fiscrihed, #he r'oiiihimiima with a main chumbiir und mesura for rupiuuiiuf thm-iin maieiiui in Svpailfi umg-ws. n' dividingA menus posi* .finned im' siibuivifling Suid chamber into u ,maries :ai miupuxfnwui's arranged mi@ beim'f im mimi :md adapted for nmiiiinihg huid imiteriulimporting means. means for ciiruhii'ing' nii', mmms fol" pwhi-atiixg air in :i piwirim-miami ((Iilpi-inturm Said :iiviliing :umm svrxiug in isolate said ums; of ma twin! wihiu wifi emnpm'tmenis and i0 diuwt i'iu: ihm* wi' the pi'vhsufeii iii? in :i haelt .h iiirwstimi 'through the main champ wifi suwwuiwiy through the vompurb usi-ms hf-win :mii into soumet, with the imeszsas within uid cmx'ipmuunts, und rshvutvrs upvmbing during riicuhition (if duil siii' im." miniitinuing the intim' and muiw mining unimpziired ils nupif'iiy for exvhaug'mg hout' for moisture. whiiu Ylwvfing thv :naamw ui :mitm-iai in a condition for the 'fnv iiiinsiuiuiion of moisture therefi'om.

154i. lu im :ippurziiius :if the dass desi-ribef, 'rim cmuhiuuiinn wiii n main chamber, and lumius fm' supxfi't'iiig therein material in Separated mames, @if iii vifiing' memi spm'ue from the materia-supporting means, said dividing humus lining contained within the main ('uiinbm amd suiidividingz' the lutter into u serie-S. if mmpiirtuunts adapted F01- wir mining thv :luifel-inl-suppmting means, means fr ciivuinirg; i vying inmii1m,saif dividing moans :smvinb tu isoiute Said masses uf materia; mii! tu dir-@Qt the How of the drying medium suvcesssiwiy through Suid vom# partmeuts and im@ cimtucf. with he masses therein, means im Vpieiu'atirurg Said drying merliiiii tu a dash-ml iimipemture, and mums [insit-ionefi in the paiiii nf the drying ruf-dimm und in the intervals between its contacts with the silccissve masses for maintaining said drying medium uit a Atennpemture which leaves each mass of material in va. transit-- fiatory condiiifm whiia-` the ccmlziiftA 0i Suid .mefiium iwith the immens effective in am;

Changing hem, for moisture.

25. An appnrims for evapnrating mnh;- ture-conmining muta-vials comprisin :i 1min chamber. divismi wuils pnsitzim'iec. ,wihin said. ciimher for dividing the Intim' into a ils Walls being positioned for 2a medium 10 partments and arranged in the line of flow of the gaseous drying medium as th(` latter circulates from one compartment to the next compartment. 4

26. An apparatus for evaporating mois turerontaining materials embodying a series of division Walls relatively arranged to produce n succession of material chambers, means for supporting material 1n separated masses within said chambers, means At'or cir- 3@ onlating a gaseous drying medium through the first chamber and successively throngh the? other chambers of the series, said diviA sion walls oierating to isolate the masses' ot material and to dircrt the flow of the drying into and through said rhamlwrs, and boosters in the line of How of thi'- dr):-Y ing medium, one of said boosters being posi-- tionecl adjacent the exit, from each chandler and tho inlet to the next succeeding chainber for rehearing the air to maintain the same at a constant temperature.

2. An apparatus for evaporatng :nulsture-containng materials embodying; a series of division walls relatively arranged to produce a succession of material cli-.nnbrrs`r means for supporting material in separated masses within said chambers, moans for feeding a gaseous drying medium to the first chamber and for circulating said drying naedium successively through the remainder of `said rlnnnbers, certain of said division walls being substantially parallel to thc planes of the material supporting means and said walls operntin to direct the flow of the drying medium tirough said chambers successiwly, and la@ serios nl' boosters in the llnc of ihrs' oli' tlndrying medium, one of said boosters bring; positioned adliarrnt the exit from each rhanher and' the inlet to the next snrreedingf rhaznlwr 'or reheatlng lh@ air s0 as to maintain the trinpemtnre ronstant.

)xn apmratns for empor-ating moislurerontaining matrriah` embodying a se los of division ,walls relatively arranged for producing a srrirs of material rhasnhers, mean? for alunni-lling material within said chambersw means for feeding a gaseous dri: ingmedilnn tothe first rhanlhor and tor vir cnlating said medium troni the first chamber sncuessivrly through the remaining rhainbers of the series, certain ot' said divlslon walls operating to isolate the masses of Inatvrial and said division walls directing the flow ot tlnA drying; inedinni through the Chaudiere siafressively. ard two series ot' boosters in the line of How of the drying medium, one of said boosters being posttioned adjacent the exit from oarh chamber and the inlet to the nextrhamher ot' the series for wheeling the nir to maintain the temperature constant.

29. ln an efalnn'ntor, a rhaniher, division walls positioned for irodnring a succession ol fion' rhannrls within said chamber. means for snpporrng material in separate masses within saidlllow rhannrls. means for feeding n menons dry-ing :iieiiinni to the first How channel and for rircnlating said niedinln through lhtsuccessivo flow channels, and boosters posit ionod in tlnxlino nl' How of the drying: medium, there lwi'g one booster adjacent the exit lll-oni each How channel and the inlet lo the neit flow channel, whereby tln` boosters relient the lair for maintaining its temperature constant during the circular tion into repeated contacts with the masses of' material.

ln testimony whereof, l have hereunto snbsrrilnd my naine.

GORDON DON HARRIS. 

